This invention relates in general to a high-efficiency oscillating shuttle pump, and in particular, to a lightweight portable shuttle pump characterized by low power consumption. Prior art pumps utilized in pumping liquid or fluids through tubes utilize a piston-type plunger which momentarily occludes the tubes to effect pumping. Such a prior art device used in circulatory assist devices is illustrated in U.S. Pat. No. 4,014,318. A prior art pump utilizing a series of pistons to successively compress, and completely occlude a tube which carries the liquid to be pumped is illustrated in FIG. 1. Pumping mechanism 10 pumps liquids through a tube 14. Three pumping pistons 11, 12 and 13 act in series to pump liquid through the tube 14. Piston 11 completely occludes tube 14. While tube 14 is held occluded, piston 12 compresses and occludes the tube 14 to urge liquid in the direction of arrow 15. The occlusion of piston 11 during compressions of tube 14 by piston 12 causes the liquid to be pumped in the desired direction. Similarly, piston 13 operates in conjunction with piston 12.
One drawback of prior art pumps is that the total occlusive nature of the pumping action reduces efficiency. Further, the occlusion utilized in such pumps has the effect of damaging cells when the pump is used to pump sensitive fluids such as blood. The shown piston relationship is relatively bulky and has a high power consumption.